U.S. patent application number 10/850538 was filed with the patent office on 2004-12-09 for access control apparatus.
Invention is credited to Echols, John C., Kaufman, Garrett, Kaufman, Peter.
Application Number | 20040247363 10/850538 |
Document ID | / |
Family ID | 33493293 |
Filed Date | 2004-12-09 |
United States Patent
Application |
20040247363 |
Kind Code |
A1 |
Kaufman, Peter ; et
al. |
December 9, 2004 |
Access control apparatus
Abstract
A keypad unit for an access system including an outer housing
having an integral bezel. A carrier is mounted within the housing,
and an overlay including key zones is mounted to the carrier. A PCB
assembly is suspended within the carrier by a non-compressive, but
compliant encapsulating compound. The PCB assembly includes a foam
layer sandwiched between a top PCB and a bottom PCB. LEDs are
electrically coupled to a top surface of the top PCB. Piezoelectric
transducers are mounted to the top PCB and are backed by the foam
layer. The carrier may include carrier projections are in register
with the key zones on the overlay and the transducers. When an
operator pushes a key zone, the corresponding projection transmits
the force via the carrier and the encapsulating compound to the
carrier adjacent the corresponding transducer causing it to
generate a voltage indicative of the pressure zone at which the
force was applied.
Inventors: |
Kaufman, Peter; (Santa
Barbara, CA) ; Kaufman, Garrett; (Carpinteria,
CA) ; Echols, John C.; (Santa Barbara, CA) |
Correspondence
Address: |
JOHN MCCULLOCH
5291 COLONY DRIVE NORTH, 1ST FLOOR
SAGINAW
MI
48603
US
|
Family ID: |
33493293 |
Appl. No.: |
10/850538 |
Filed: |
May 20, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60471873 |
May 20, 2003 |
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Current U.S.
Class: |
400/472 |
Current CPC
Class: |
B60R 25/23 20130101;
G07C 9/0069 20130101 |
Class at
Publication: |
400/472 |
International
Class: |
B41J 005/08 |
Claims
What is claimed is:
1. A keypad unit for an access system, said unit comprising: an
outer housing having walls defining a housing cavity; an internal
carrier mounted within the housing cavity, said internal carrier
including walls defining a carrier cavity means forming a plurality
of indicia zones overlying said carrier; a circuit board assembly
including a resiliently compressive layer and at least one circuit
board having a plurality of transducers; and a non-compressive, but
compliant encapsulating compound confined within the carrier
cavity, said circuit board assembly being suspended within the
encapsulating compound, said compressive layer separating the
encapsulating compound from said transducers.
2. The unit according to claim 1 wherein the encapsulating compound
has a hardness within the range of between about Shore A 20 and
80.
3. The unit according to claim 1 wherein the encapsulating compound
is a cast resin.
4. The unit according to claim 1 wherein the compressive layer is a
foam layer.
5. The unit according to claim 4 wherein the foam layer is an
acrylic material.
6. The unit according to claim 1 including an overlay overlaying
said transducers, said overlay comprising a flexible,
non-compressive material.
7. The unit according to claim 1 wherein the internal carrier
includes a plurality of carrier projections extending into the
carrier cavity and in register with the transducers.
8. The unit according to claim 1 wherein said encapsulating
compound is wholly confined within said carrier cavity.
9. The unit according to claim 1 wherein the keypad unit is
applicable to be mounted to a door of a vehicle, and the access
system is a vehicle access system.
10. A keypad unit for an access system, said unit comprising: an
outer housing; an internal carrier mounted within the housing and
defining a carrier cavity; a printed circuit board assembly
including at least one printed circuit board, said at least one
printed circuit board including a plurality of piezoelectric
transducers; and a non-compressive, but compliant encapsulating
compound contained within the carrier cavity, said printed circuit
board assembly being suspended within the encapsulating
compound.
11. The unit according to claim 10 further comprising a resiliently
compressive layer positioned between the transducers and the
encapsulating compound.
12. The unit according to claim 11 wherein the compressive layer is
a foam layer.
13. The unit according to claim 10 wherein the encapsulating
compound is a translucent or transparent cast resin and has a
hardness within the range of about Shore A 20 to Shore A 80.
14. The unit according to claim 13 wherein the encapsulating
compound has a hardness of about Shore A50.
15. The unit according to claim 10 further comprising an overlay
overlying a top wall of the carrier, said overlay including a
plurality of key zones.
16. The unit according to claim 15 wherein the overlay is a
flexible, non-compressive polyurethane layer.
17. The unit according to claim 10 wherein the internal carrier
includes a plurality of carrier projections extending into the
carrier cavity and in register with the transducers and the key
zones.
18. The unit according to claim 10 wherein the keypad unit is
applicable to be mounted to a door of a vehicle, and the access
system is a vehicle access system.
19. A keypad unit for an access system associated with a vehicle,
said keypad unit having means for mounting said unit to a vehicle
door, said unit comprising: an outer housing defining a housing
cavity and having an integral bezel; a transparent or translucent
internal carrier mounted within the housing cavity, said internal
carrier including a top wall and sidewalls defining a carrier
cavity, said carrier further including a plurality of carrier
projections extending into the carrier cavity; an overlay mounted
to an outside surface of the top wall of the carrier, said overlay
including a plurality of key zones in register with the carrier
projections; a printed circuit board assembly including a resilient
foam layer sandwiched between a top printed circuit board and a
bottom printed circuit board, said top printed circuit board
including a plurality of LEDs positioned between the top wall of
the carrier and the printed circuit board assembly where the LEDs
are in register with the key zones, said top printed circuit board
further including a plurality of piezoelectric transducers mounted
to the top printed circuit board and backed by the foam layer, said
piezoelectric transducers being in register with the carrier
projections; and a non-compressive, but compliant encapsulating
compound combined within the carrier cavity, said printed circuit
board assembly being suspended within the encapsulating compound
and being spaced from all walls of the carrier.
20. The unit according to claim 19 wherein the encapsulating
compound is a translucent or transparent cast resin.
21. The unit according to claim 19 wherein the overlay is a
flexible, non-compressive polyurethane layer.
22. The unit according to claim 19 wherein the encapsulating
compound has a hardness within the range of about Shore A 50.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of the filing date of
U.S. Provisional Application No. 60/471,873, titled "Access Control
Apparatus," filed May 20, 2003.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to a keypad unit and, more
particularly, to a keypad unit for controlling access to a vehicle,
compartment, premises, or other areas to which access desirability
is restricted to authorized personnel.
[0004] 2. Discussion of the Related Art
[0005] Access control systems for vehicles and the like sometimes
employ a keypad unit mounted to a vehicle door. The vehicle
operator may apply touch pressure to keys on the keypad unit in a
predetermined number sequence, which will in turn unlock the door.
Because these keypad units are employed on the outside of the
vehicle, they are subject to weather conditions and potential
vandalism. Therefore, keypad unit designs require that the keypad
unit be adequately sensitive to a person's touch, and be weather
resistant and tamper resistant. A keypad unit of the general type
to which the invention relates is disclosed in U.S. Pat. No.
5,674,018 issued Oct. 7, 1997 to Kaufman et al.
SUMMARY OF THE INVENTION
[0006] A keypad unit constructed in accordance with the present
invention includes an outer housing having an integral bezel. A
carrier is mounted within the housing and an overlay including
numbered zones is mounted to a top surface of the carrier. A PCB
assembly is suspended within the carrier by a non-compressive, but
compliant encapsulating compound so that the PCB assembly is
hermetically sealed and is positioned away from the carrier. The
PCB assembly includes at least one PCB and a compressive layer.
LEDs are electrically coupled to a top surface of the PCB.
Piezoelectric transducers are mounted to the PCB and are backed by
the compressive layer. In one embodiment, the carrier includes
carrier projections oriented relative to the numbered zones and the
piezoelectric transducers. When an operator pushes on one of the
zones, the corresponding projection on the carrier transfers the
force to the piezoelectric transducer, which flexes relative to the
compressive layer, causing it to generate a voltage indicative of
the site of the applied force.
[0007] Additional advantages and features of the present invention
will become apparent from the following description and appended
claims, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is an isometric view of a keypad unit of the kind
adapted for use with a vehicle, where the keypad unit is mounted to
a vehicle door;
[0009] FIG. 2 is an end view of the keypad unit shown in FIG. 1
separated from the vehicle;
[0010] FIG. 3 is a front view of a housing of the keypad unit shown
in FIG. 1
[0011] FIG. 4 is a cross-sectional view through line 44 in FIG. 3
of the keypad unit;
[0012] FIG. 5 is a rear isometric view of a circuit board carrier
removed from the keypad unit shown in FIG. 1;
[0013] FIG. 6 is a top view of a printed circuit board (PCB)
assembly employed in the keypad unit shown in FIG. 1; and
[0014] FIG. 7 is a cross-sectional view of the PCB assembly shown
in FIG. 6.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0015] The following discussion of the embodiments of the invention
directed to a keypad unit for an access system associated with a
vehicle is merely exemplary in nature, and is in no way intended to
limit the invention or its applications or uses.
[0016] FIG. 1 is an isometric view of a keypad unit 10 that is part
of an access system for a vehicle. The keypad unit 10 is shown
mounted to a vehicle door 12. However, as will be appreciated by
those skilled in the art, the keypad unit 10 can be mounted to
other parts of the vehicle, or be employed in systems other than an
access system for a vehicle. FIG. 2 is an end view and FIG. 4 is a
cross-sectional view of the keypad unit 10 separated from the door
12. The keypad unit 10 includes an overlay 14 having a plurality of
indicia or key zones 16, where the key zones 16 include numbers or
other indicia. In this embodiment, there are five key zones 16,
each including two numbers. An operator will enter a predetermined
number code by pressing the zones 16 in a certain sequence. By
pressing the proper sequence of the zones 16, the unit 10 will
cause the access system to unlock the door 12.
[0017] The unit 10 includes an outer housing 24 having a mounting
flange or bezel 26, a sidewall 28 and a rear wall 30 that combine
to define an internal cavity 32. FIG. 3 is a front view of the
housing 24. The bezel 26 is supported on the exterior of the
vehicle door 12 by bolts positioned within holes 22 extending
through the bezel 26. The arrangement of the bezel 26, the sidewall
28 and the rear wall 30 are such to enable the zones 16 to be
visible to the vehicle operator. The housing 24 is made of any
suitable opaque metal or plastic that is molded as a single piece
unit to provide the desired rigidity.
[0018] The unit 10 further includes an internal carrier 40 having a
deflectable force transmitting top wall 42 and sidewalls 44 which,
together, form a cavity closed at its rear by the rear wall 30 of a
housing 24. FIG. 5 is a rear isometric view of the carrier 40
separated from the unit 10. In one embodiment, the carrier 40 is a
molded plastic resin, such as a nylon resin. This molded resin is
highly impact resistant, UV resistant, and is able to allow an
encapsulating compound, discussed below, to be readily adhered to
it. The carrier 40 may be translucent or transparent to allow light
to pass through it. The top wall 42 seats on a shoulder 50. The
overlay 14 is mounted to a top surface of the top wall 42 by, for
example, a double-sided piece of adhesive tape. In an alternate
embodiment, the overlay 14 can be eliminated, and indicia can be
formed on either side of the top wall 42 of the carrier 40 by any
suitable technique.
[0019] A PCB assembly 48 is suspended within the carrier 40 by a
non-compressive, but compliant (non-rigid) encapsulating compound
52. The assembly 48 and the compound 52 completely fill the carrier
cavity, thereby precluding any lateral expansion of the compound
52. The compound 52 is non-compressive, but compliant in that a
force applied to the compound 52 is transmitted throughout the
compound 52 without the compound 52 compressing within the closed
or contained environment. The compound 52 is also translucent or
transparent to allow light to pass through it. In one embodiment,
the compound 52 is an encapsulating resin, such as an unfilled,
cast epoxy, having a Shore hardness within a selected range of
between 20 and 80. A shore hardness of about A50 is satisfactory.
the compound also may have a density of about 8.8 wpg and a
compressive strength of about 425 psi. By suspending the PCB
assembly 48 in the compound 52 within the cavity of the carrier 40,
the fragile components of the unit 10 are protected from the
environment and spaced from the carrier walls.
[0020] FIG. 6 is a top view of the PCB assembly 48 and FIG. 7 is a
cross-sectional view of the PCB assembly 48 separated from the unit
10. The PCB assembly 48 includes a top PCB 54 and a bottom PCB 56
separated by a resiliently compressive layer 58 formed from
suitable material such as a closed cell acrylic foam. A series of
LEDs 62 are electrically coupled to the top PCB 54 and are in
register with the key zones 16 to illuminate them in low ambient
conditions. In one embodiment, the overlay 14 is opaque and the
indicia on the key zones 16 is translucent so that light from the
LEDs 62 illuminates the indicia through the compound 52 and the
carrier 40. The PCBs 54 and 56 include electrical components
suitable for the operation of the unit 10, such as those disclosed
in the '018 patent.
[0021] A series of transducers 64 are mounted to the rear surface
of the PCB 54 and are also oriented relative to the key zones 16.
In an alternate embodiment, the transducers 64 can be mounted to
the top surface of the PCB 54. The transducers 64 can be any
transducer suitable for the purposes described herein, such as a
piezoelectric bender or force sensitive resistor. A piezoelectric
bender includes a piezoelectric wafer sandwiched between a pair of
electrodes. Piezoelectric benders suitable for use in the
embodiment disclosed herein are disclosed in the '018 patent. As is
well understood in the art, deformation or compression of the
transducer 64 generates a voltage. When the transducers 64 are
flexed against the compressive layer 58, a signal is sent to the
appropriate circuitry on the PCB 56. The sequence of flexing the
transducers 64 generates a code that is processed to open the door
12 by the access system. Wires 72 electrically coupled to the PCB
56 extend through the compound 52 and a tightly fitting opening 74
in the rear wall 30 of the housing 24, as shown, to be connected to
the access system.
[0022] The transducers 64 are positioned against and backed by the
compressive layer 58 and are encapsulated by the compound 52. The
compressive layer 58 is secured to the PBC 54 by a suitable
adhesive. The compressive layer 58 also prevents the compound 52
from contacting the transducers 64, which otherwise could adversely
affect the transducers' ability to flex in response to the
application of force by the operator. In an alternate embodiment,
the transducers 64 can be compression transducers, and the
compressive layer 58 can be eliminated. Also, in other embodiments,
the PCB 56 can be eliminated, and its electronics supported on the
PCB 54, or the PCB 56 can be outside of the unit 10.
[0023] As discussed above, the transducers 64 are intended to flex
in response to force applied to the key zones 16. In one
embodiment, the carrier 40 employs a series of carrier projections
70 that are in register with the key zones 16 and the respective
transducers 64, as shown. When the operator applies force to the
key zone 16, the appropriate location, which causes the transducer
64 to flex against the compressive layer 58. The transducer 64
generates the voltage signal that indicates one of the key zones 16
has been pressed. It is stressed, however, that the projections 70
assist, but are not required in the transfer of force to the
transducers 64.
[0024] The construction of the keypad unit 10, including the
confined compound 52, allows the unit 10 to experience the
application of excessive force abuse and prolonged use without the
unit 10 failing or becoming damaged. The compressive layer 58 is
combined within the carrier 40, and the PCB assembly 48 is
suspended within the encapsulating compound 52 away from the
operable surface of the overlay 14. The PCB assembly 48 including
the transducers 64, is thus separated from the surface of the unit
10 within a compliant boundary layer.
[0025] The foregoing discussion discloses and describes merely
exemplary embodiments of the present invention. One skilled in the
art will readily recognize from such discussion and from the
accompanying drawings and claims that various changes,
modifications and variations can be made therein without departing
from the spirit and scope of the invention as defined in the
following claims.
* * * * *